Organizational Unit:
Space Systems Design Laboratory (SSDL)
Space Systems Design Laboratory (SSDL)
Permanent Link
Research Organization Registry ID
Description
Previous Names
Parent Organization
Parent Organization
Organizational Unit
Includes Organization(s)
ArchiveSpace Name Record
Publication Search Results
Now showing
1 - 3 of 3
-
ItemMoon-based Advanced Reusable Transportation Architecture(Georgia Institute of Technology, 2001-07) Nelson, Douglas K. ; Marcus, Leland R. ; Bechtel, Ryan S. ; Cormier, Timothy A. ; Weglian, John E. ; Alexander, R.Abstract: The Moon-based Advanced Reusable Transportation Architecture (MARTA) Project conducted an in-depth investigation of possible Low Earth Orbit (LEO) to lunar surface transportation systems capable of sending both astronauts and large masses of cargo to the Moon and back. The goal of this project was to create a profitable venture with an Internal Rate of Return (IRR) of 25%. The architecture was quickly narrowed down to a traditional chemical rocket using a liquid oxygen and liquid hydrogen. However, three additional technologies identified as potentially cost saving were: aerobraking, in-situ resource utilization (ISRU), and a mass driver on the lunar surface. The vehicle was modeled using the Simulated Probabilistic Parametric Lunar Architecture Tool (SPPLAT) that incorporated several different engineering disciplines. This tool used ISRU propellant cost, a dry weight reduction due to improved materials technology, and vehicle engine specific impulse as inputs and provides vehicle dry weight, total propellant used per trip, and price to charge the customer in order to guarantee an IRR of 25% as outputs. Estimation error, market growth, and launch cost uncertainty were also considered. The results of the project show that the desired operation is possible using current technology. Based on the stipulation that the venture be profitable, the price to charge the customer was highly dependent on ISRU propellant cost and relatively insensitive to the other inputs. With the best estimate of ISRU cost set at $1000/kg, the resulting price to charge the customer was $2600/kg of payload from LEO to the lunar surface. If ISRU cost can be reduced to $160/kg, the price to the customer is reduced to just $800/kg of payload. Additionally, the mass driver only proved to be cost effective at an ISRU propellant cost greater than $250/kg, although it reduced total propellant used by 35%.
-
ItemT-BEAT: A Conceptual Design Tool for Turbine-Based Propulsion System Analysis(Georgia Institute of Technology, 2001-05) Bechtel, Ryan S.The extreme cost, high risk and technological difficulty of access to space are all key factors hindering mankind's continued exploration of the solar system. As a result, safe, low-cost and technically feasible vehicle concepts are constantly being explored. One such concept currently receiving interest is the use of turbine engines as part of a launch vehicle’s propulsion system. These turbine engines may be utilized during the boost phase of a two-stage launch vehicle or part of a combined cycle engine on a single-stage-to-orbit vehicle. Although turbine engines themselves have reached a high level of maturity in the aircraft industry, their use in space launch systems is at a relatively low development level. As a result, much of the inquiry into vehicle types utilizing turbine engines is being performed at the conceptual level. At the conceptual level of design it is possible to explore many options and engine types since costs are relatively low, and design freedom is large. It is therefore helpful to have a design tool that allows rapid analysis of many engine types and configurations over a wide range of operating conditions. The Turbine-Based Engine Analysis Tool, T-BEAT, has been created to fulfill such a need. T-BEAT was written in C++ and can be run either directly from a UNIX workstation or remotely through the World Wide Web. The program can analyze many configurations including a turbojet, afterburning turbojet, ramjet, and turbine-based combined-cycle engine. T-BEAT provides thrust and Isp for off-design conditions set by the user. The output can be retrieved in the form of a POST engine deck, which helps speed up the design process. Validation for the program was performed using existing codes.
-
ItemExploration of the Design Space for the ABLV-GT SSTO Reusable Launch Vehicle(Georgia Institute of Technology, 2000-09) Bradford, John Edward ; Olds, John R. ; Bechtel, Ryan S. ; Cormier, Timothy A. ; Messitt, Donald G.The ABLV-GT is a conceptual design for an advanced reusable launch vehicle based on the current NASA Langley ABLV concept. It is a Vision Vehicle class, horizontal takeoff, horizontal landing singlestage-to-orbit vehicle. Main propulsion is provided by Aerojet's 'Strutjet' LOX/LH2 rocket-based combined cycle engine design. The ABLV-GT is designed to deliver 25,000 Ibs. to the orbit of the International Space Station from Kennedy Space Center. This paper will report the findings of a conceptual design study on the ABLV-GT performed over the last year by members of the Space Systems Design Lab at Georgia Tech. This work has been sponsored by the Advanced Reusable Transportation Technologies program office at NASA Marshall Space Flight Center. Details of the concept design including external and internal configuration, mass properties, trajectory analysis, aerodynamics, and aeroheating are given. This vehicle study resulted in the closure of 18 different vehicle designs. The trade variables included air-breathing transition Mach number, mechanical versus thermal choke engine, and payload weight. Initial results for a vehicle with a turbine-powered lowspeed propulsion system were generated and will be presented. Finally, a low earth orbit concept with a reduced payload weight will be shown.